Manually controlled tracer



March 2, 1948. H, w, GALE 2,437,190 MAUALLY coNTRoLLED TRACER Filed July 26, 1944 2 Sheets-Sheet l March 2, 1948. H. w. GALE MANUALI!!v CONTROLLED TRACER 2 Sheets-sheet `2 Filed July 26, 1944 Y 2..- f nani 5mg/5M,

Attorne 5 "Patented Mar. 2, 1,948

i f I i 2,437,190

MANUALLYY CONTROLLED TRACER Harold W. Gale, Dearborn, Mich., assignor to Hexagon Tool and Engineering Corporation,

Dearborn, Mich.

Application July 26, 1944, Serial No. 546,683

3 Claims.

This invention relates to new and-useful improvements in engravers and more particularly to a novel contourlng and proling hand tracer.

An important object of the invention is to provide an engraver of the character stated which may be used with all types of lathes, milling machines and planers on work which has an irregular surface and must be tted to Ia template, pattern or model.

Another important object of the invention is to provide :a device of the character described whereby lighter pressures between the tracer element or unit and pattern are rendered possible so that other than metal patterns, models or the like may be utilized.

Various other important objects and advantages of the invention will become apparent to the reader of the followingY description.

In the drawings- Figure 1 represents a side elevational view of the tracer or pilot, showing a holder therefor in dotted lines.

Figure 2 is a. top plan View of the structure shown in Figure l.

Figure 3 is a vertical sectional and elevational view through the device.

Figure 4 is a horizontal section on the line 4-4 of Figure 3 looking in the direction of arrows.

Figure 5 is a side elevational View, with a portion in section, showing a slightly 'inodied form of feeler unit or means.

Figure 6 is a top plan view of the semi-spherical adapter member Iappearing in Figure 3.

Figure 7 is a side elevational View of the follower disk unit.

Referring to the drawings wherein like numerals designate like parts, it can be seen that numeral 5 generally refers to the improved tracer which may be supported by a suitable bracket or the like 6.

At this point, it is to be understood that this tracer or pilot is to be used in the capacity of the corresponding mechanism of the patent to Romaine,`No. 2,076,865, and in conjunction with the same type of indicating instruments,

The tracer consists of a barrel l having -a substantially large bore 8 extending inwardly from one end and merging with an annular tapered seat 9 into which opens a smaller bore IB, which, at its lower end, merges with -a beveled annular seat Il, the lower end of the barrel being open, as shown in Figure 3. Y

The upper end of the barrel is externally threaded to engage the internal threads of -a cap l2 having a central opening in the tcp thereof through which a pin I3 projects. The pin I3 projects from a shank I4 rising from a pressure and follower disk l5 which has a depending bevel edged skirt I6 co-acting and mating engagement withthe inner perimeter of upstanding undercut annular lip I'I on a semi-spherical-shaped body I8 resting rockably on the seat 9 and which has a special socket I9 in the bottom portion thereof for receiving the reduced head 2i) of an upwardly tapering stem 2l rising from a ball 22. A projection 23 depends from the ball 22 rand has la reduced screw-stud Z'disposed into a semi-spherical pattern rider or feeler 25.

Instead of the reduced head 2i! being located in an undercut socket I9, a body lila (see modiiication in Figure 5) may be formed with a-recess I9a into which a small ball head 29a can be removably disposed, this being located at the upper end of a stem 2Ia projecting upwardly from a ball 22a corresponding to the ball 22.

It will be noted that a coiled compression spring 26 is interposed between vthe disk I5 and the cap I2 for the purpose of maintaining the pressure disk I5 urged downwardly in 'interlapping position with respect to the body I8 and the body I8. in turn,` snugly against the seat 9.

The purpose of the circumferential lip I7, since the center line of annular rib I5a falls on the center line I0l" the body, is to hold the adapter body I8 in place and central with the main bore 8 when the body is tipped past ,axial center. Also the inside surface of lip II is so counterbored as to clear the beveled surface of -skirt I and also serves las a stop when thebody I8 is tilted to its extreme position.

The opening, socket IS, is a tapered hole merging into a straight hole bored to fit ball 2i! and ending in an angle. The tapered portion of the hole is clearance for the stem 2i .and it also acts as a stop when the body is revolved to its extreme position. The ball 20 is easily removed from the socket. The only difference between socket I9 :and socket I9a is the tapered portion of the hole. l

It will be noted in Figure 5 that ball 20a is located by a circular center line passing through the-center of :annular rib I5a and also ball 22a is located similarly by a circular center line drawn through the center of the corresponding radius of body Ilia. This radius is tangent to the circumference and above the center of the body Ita.

The pressure disk for the design shown in Figure 5 is not shown but is similar to I5 excepting that it has no skirt It,

It will be noted that the skirt IG rides on radius Ilia.

A lathe job, for example, which has an irregular shaped hole, one that flares out like a bell, would be machined in this manner: The work, of course, would be held in a chuck and the required surfaces finished before machining the curve in the hole. A templet made of a at piece of metal or wood, having the saine contour as 'the bell-shaped hole, is fastened horizontally on some stationary part of the lathe and lined up so that its curve will be in the same relative position as the curve to be out in the hole. The hand tracer is fastened to that part of the carriage 'of the lathe which holds the cutting tool. Any movement of the cutting tool has a corresponding movement of the hand tracer or instrument. The -instrument is also fastened in such a manner that the tracer or feeler 25 will touch the curved surface of the templet. As the tracer touches the templet, the' plunger moves out and registers on an indicator (not shown) registering in thousandths of 'an inch. The exact amount it moves out is determined by the operator and the dial is set on zero. As the cutting tool is feeding in and the tracer approaches and touches the templet, the operator waits until the hand on the indicator reads zero. Then, by hand, he moves the cutting tool away from the work 'a few thousandths of an inch and this process is continued 'until the full out has been made or completed. This is a typical contouring operation. Contouring operations are also often made on the 'other ina chinos above mentioned.

'This instrument is only used with an indicator, registering in thousandths of an inch, a dial in dicator being preferred. The tracer is free to move in all directions causing the plunger to move out. rlhe indicator is fastened to the bracket shown, or one similar to it. It will be noted that any side pressure on the tracer causes a rocking motion `of the rocker i3. An upward pressure permits the entire slidable and turnable unit to move up within the barrel.

While the foregoing specification sets forth the invention in specific terms, it is to be understood that numerous changes in the shape, size and materials may be resorted to without departing from the spirit and scope of the invention as claimed hereinafter.

Having described the invention, what is claimed as new is:

1. A tracer `of the class described comprising a longitudinally elongated, centrally bored barrel having a reduced portion at its lower end provided with an annular beveled seat, the upper portion of the bore being circumferentially enlarged and the intermediate portion being provided with an annular beveled seat merging into said reduced portion, an adapter body of general semi-spherical form located in the upper portion of the bore and engaging the adjacent beveled seat, a spring-pressed end thrust pressure unit mounted in the upper portion of the bore and engaging the adapter, a stem having its major portion' located in the reduced portion'of the bore, its upper end universally connected with the central portion of said member, and its intermediate portion provided with a bail-joint element engageable with the beveled seat at the outer end of the reduced part of the bore, said stem projecting beyond said barrel to accommodate a Adetachable tracer element.

2. A tracer of the class described comprising a centrally bored, longitudinally elongated barrel, the lower portion of the barrel being reduced in diameter and provided with an annular beveiled seat and the upper portion enlarged and the intermediate portion merging into a beveled annularseat adjoining the reduced and enlarged portions of said bore, a longitudinally and axially rotatable stern located in the reduced portion and provided with a ball-joint element engaging the 'seat in the reduced portion of the barrel, said stem Vprojecting outwardly beyond said barrel and carrying a semi-spherical feeler, a semi-spherical adapter member rockably and shiftably engaging the beveled seat in the intermediate portion of the bore, the upper end of said stem having a universal connection with the lower central portion of said member, the upper end portion oi said member having an annular bead semi-cylindrical in cross-sectional form, and a marginal upstanding lip projecting above said bead, said lip having its inner peripheral edge undercut, a removable cap on the upper end 'of said barrel, an end-thrust unit in the upper portion of the bore comprising a shank extending up through the cap, and a disk-like head on the lower end of said shank, said head riding movably against the adjacent wall vportieri of the bore and being provided with a reduced bevel-edged skirt, said skirt telescoping into 'the upper portion of said member and resting on said bead with its beveled surface co-acting with the undercut inner peripheral surface of `said lip, together with a coiled spring surrounding said shank and resting on the disk at one end and against the cap at the opposite end.

3. As a new article of manufacture and as a component part of a hand tracer of the class described, a semi-spherical adapter member adapted to be rockably and shiftably mounted in a cylindrical barrel in contact with a supporting seat in said barrel comprising a semi-spherical body provided on its fiattened end with an annular rib, said rib being semi-cylindrical in crosssectional form and arranged concentrically at a point inwardly of the outer marginal edge of the body, said outer marginal edge being provided with an endless annular upstanding lip, this projecting above and beyond said rib, and said lip having its inner peripheral edge undercut, the central portion of the under crown of the con- Vex portion of the body being provided with a socket to accommodate -a ball joining element on a tracer carrying stem.

HAROLD YV. GALE.

REFERENCES CITED The following references are of record in the ille of this patent:

UNITED STATES PATENTS Number Name Date 340,582 Keim Apr. 27, 1386 1,213,582 Brown Jan. 23, 1917 1,788,894 Sohjolin Jan. 13, 1931 1,790,168 Paul Jan. 27, 1931 1,952,231 Anderson Mar. 27, 1934 1,966,618 Egorenkov July 17, 1934 1,977,015 Rodier Oct. 16, 1934 2,007,899 Shaw July 9, 1935 2,076,865 Romaine Apr. 13, 1937 2,087,049 Shanley July 13, 1937 2,101,712 Johansen Dec. 7, 1937 

